Ashing method and ashing device

Abstract

An ashing device and ashing method that can positively remove resist from a wafer while preventing degradation of the film material properties of exposed porous Low-K film on the wafer. The ashing device of the present invention introduces a gas to a dielectric plasma generating chamber 14 , excites said gas to generate a plasma, and performs plasma processing using said gas plasma on a processing work S in use of a Low-K film. The ashing gas introduced from a gas regulator 20 is an inert gas to which H 2 has been added. The configuration is formed so that plasma is generated from the gas blend, and the resist is removed by the hydrogen radicals generated.

The invention claimed is: 
     
       1. An ashing method of introducing a gas to a plasma generating chamber formed, at least in part of dielectric material, exciting said gas to generate a plasma, and performing plasma processing using said gas plasma on a processing subject in use of Low-K film, said method comprising the steps of:
 introducing a gas blend to said plasma generating chamber, wherein the gas blend is prepared as a result of preparing an inert gas to which H 2  has been added at a weight ratio between 1% and 20% on a mass basis, wherein H 2 O is also added at a weight ratio between 0.1% and 5% on a mass basis to said inert gas to which H 2  has been added; and 
 generating plasma by exciting said gas blend and removing resist on said processing subject by hydrogen radicals that are generated. 
 
     
     
       2. The ashing method according to  claim 1 , wherein said inert gas comprises He. 
     
     
       3. The ashing method according to  claim 1 , wherein:
 said Low-K film is positioned as an insulating layer between at least two integrated circuit layers of a chip, and 
 the steps of generating said plasma by exciting said gas blend and removing said resist on said processing subject are performed after forming said Low-K film on a substrate and after etching said Low-K film using said resist as a mask. 
 
     
     
       4. The ashing method according to  claim 3 , wherein the steps of generating plasma by exciting said gas blend and removing said resist on said processing subject further generate oxygen radicals, increase an ashing rate of said resist and suppress change in a dielectric constant of the Low-K film. 
     
     
       5. An ashing method of introducing a gas to a plasma generating chamber formed, at least in part of dielectric material, exciting said gas to generate a plasma, and performing plasma processing using said gas plasma on a processing subject in use of Low-K film, said method comprising the steps of:
 introducing a gas blend to said plasma generating chamber, wherein the gas blend is prepared as a result of preparing an inert gas to which H 2  has been added at a weight ratio between 1% and 20% on a mass basis, wherein O 2  is also added at a weight ratio between 0.01% and 0.1% on a mass basis to said inert gas to which H 2  has been added; and 
 generating plasma by exciting said gas blend and removing resist on said processing subject by hydrogen radicals that are generated. 
 
     
     
       6. The ashing method according to  claim 5 , wherein said inert gas comprises He. 
     
     
       7. The ashing method according to  claim 5 , wherein:
 said Low-K film is positioned as an insulating layer between at least two integrated circuit layers of a chip, and 
 the steps of generating said plasma by exciting said gas blend and removing said resist on said processing subject are performed after forming said Low-K film on a substrate and after etching said Low-K film using said resist as a mask. 
 
     
     
       8. The ashing method according to  claim 7 , wherein the steps of generating plasma by exciting said gas blend and removing said resist on said processing subject further generate oxygen radicals, increase an aching rate of said resist and suppress change in a dielectric constant of the Low-K film.